I was constantly banned from subreddits only recently (past 2 years or so). When I would ask them to show me the rule I broke, the mods would just say something along the lines of, "you don't have to break a rule since bans are at mod discretion, yada, yada, yada." Basically, I was only offending their delicate sensibilities that they didn't care to share. I finally threw my hands up and haven't been back in months. Guess I should formally wrap it up by finally deleting my decade old account.

Mods for individual subreddits can do whatever they want with their own subreddits. That is completely different issue from the reddit admins that run the whole site.

Correct, and most of the mods I've encountered are very user-hostile. I miss the times when the admins would smack them down for that kind of crap. Oh well, the times they are a changin'!